A scalpel (scalpel) consists of a handle and a detachable blade. Generally speaking, tool handles are classified according to their length and size (Figure 3- 1), and several different types of blades can be installed on a tool handle. There are many kinds of blades, which can be divided into round knives, curved knives and triangular knives according to their shapes. According to its size, it can be divided into large blades, medium blades and small blades (Figure 3-2). Choose the appropriate handle and blade according to the actual needs during the operation. 【 Clinically, only 10 blade (round knife),1blade (sharp knife), 15 blade (small round knife) and 22 blade (round knife) are used to make long abdominal incision. 10 blade abdominal skin resection, compared with open surgery, its surgical incision and trauma are smaller. A round knife is not as sharp as a sharp knife, but it has the advantage of good controllability. Of course, if you cut the abdominal skin with a 15 small round knife, it will definitely make you depressed to death. 15 small round knife-double eyelid surgery, cut the upper eyelid skin. Because it is small, it is flexible. The first choice for facial plastic surgery. 1 1 sharp knife-bilateral pouch removal and eyelid skin incision. Because the drooping skin of the lower eyelid is heavier than that of the upper eyelid, it is difficult to cut it with a round knife. Imagine cutting the skin repeatedly with a round knife. Basically, this patient will be disfigured. But a sharp knife is easy to break, especially its tip. It is not suitable for cutting high-strength tissues, such as thick skin and tendons. Blade 12 (machete) is commonly used in otolaryngology. Tracheotomy 15 is also used to cut fine tissues or skin flaps in hand surgery.